Internalization of Pseudomonas aeruginosa is mediated by lipid rafts in contact lens-wearing rabbit and cultured human corneal epithelial cells

Naoka Yamamoto, Nobutaka Yamamoto, Walter M Petroll, Harrison D Cavanagh, James V. Jester

Research output: Contribution to journalArticlepeer-review

43 Scopus citations

Abstract

PURPOSE. The internalization of Pseudomonas aeruginosa (PA) in nasal and tracheal epithelium has recently been shown to involve the formation of cholesterol- and sphingolipid-rich plasma membrane domains (lipid rafts). The purpose of this study was to investigate the role of lipid rafts in PA internalization by corneal epithelium in vivo, in vitro, and after contact lens wear. METHODS. Lipid raft formation was evaluated in rabbit corneas with and without contact lens wear and a human corneal epithelial (hTCEpi) cell line before and after PA infection with cornea-pathogenic strains by staining with FITC-conjugated cholera toxin β-subunit, known to bind the lipid raft component GM1. Bacterial internalization was assessed by gentamicin survival assay. The role of lipid rafts in PA internalization was evaluated by pretreatment of hTCEpi cells with cholesterol metabolism inhibitors. The interaction of PA with lipid rafts was confirmed by flow cytometry. RESULTS. Contact lens wear in rabbits induced lipid raft formation in occasional surface corneal epithelial cells. Subsequent PA exposure showed preferential binding to lipid raft-forming cells, leading to lipid raft aggregation and PA internalization. A similar sequence of lipid raft formation and PA internalization was also observed in hTCEpi for all PA strains. Internalization of all PA strains was blocked by three cholesterol metabolism inhibitors (P < 0.01). Flow cytometry showed an association of PA with rafts. CONCLUSIONS. These findings demonstrate that contact-lens-mediated PA internalization involves lipid raft formation. Also, hTCEpi cells may be used as an experimental model for studying further the molecular mechanism(s) of PA infection in the corneal epithelium.

Original languageEnglish (US)
Pages (from-to)1348-1355
Number of pages8
JournalInvestigative Ophthalmology and Visual Science
Volume46
Issue number4
DOIs
StatePublished - Apr 2005

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

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